This set of Casting, Forming and Welding Multiple Choice Questions & Answers (MCQs) focuses on “Finishing of Cores”.
1. How are core manufactured in casting?
a) Cores are manufactured from a pattern in the same way as of mold
b) Cores are manufactured by machining process
c) Cores are manufactured by traditional methods
d) Cores are not manufactured, they are found naturally
Explanation: The manufacturing of cores is all similar to mold making and ramming.
2. What are the core boxes?
a) Used to support cores
b) Used to create cores
c) Used to store cores
d) Used to Eject cores while ejection of casting after solidification
Explanation: Core boxes are those elements or tools which are used to create cores.
3. In the case of coldbox core _____________
a) The core mix is heat treated in order to cure it
b) Core mix immediately gets cured after sand is blown
c) Time is given to the core mix to be cure
d) Cold water is poured onto the core mix
Explanation: Due to high production rates, the coldbox are left alone to cure by itself after the sand is blown into the corebox.
4. In the case of shell, hotbox or warmbox ______________
a) Hot water is poured onto the sand mixture
b) The sand mixture is heated to set the core
c) Steam is provided to the core mix
d) The corebox is left in the room temperature
Explanation: The sand mixture needs to be heated in order to set the core. Once, it is set the core is removed from the corebox.
5. What will happen if the parting line in the corebox is not closed properly?
a) Coresand may blow out of the box to create fins on the cores
b) The cope and drag part clamped will detach and break the core
c) Air inclusion occurs as the atmospheric air involves the solidification of core
d) Nothing will happen, as the parting line has no role in core making
Explanation: Obviously, the sand will overflow out causing unwanted contours called fins, which may increase the cost of machining to remove them and time is consumed.
6. Why the air already present inside the corebox is necessary to be evacuated before pressurised air is blown into it?
a) The air has comparatively low pressure hence, distortion occurs
b) Hot tears will occur on the surface
c) It will cause poor sand distribution and poor compaction
d) Nothing will happen as the pressure of incoming air neutralises inside air pressure
Explanation: The air inside the corebox does not get enough time to escape hence sand distribution and compaction is poor.
7. Why should the finishing of core be made good enough?
a) The intricate shapes made are difficult for machine finishing
b) The size of the cavities and contours must be accurate to enable perfect assemblies
c) It reduces machining cost and time invested for that
d) All of the above
Explanation: The cores are used where machining cost or time is the foundation or is difficult to achieve and hence finishing is done on the core itself.
8. Match the elements in box ‘A’ to their respective functions in box ‘B’ and tick the correct option.
|1 – CORE||a – ARE USED TO PRODUCE CORES|
|2 – CORE PRINT||b – ARE USED TO PROVIDE SUPPORT TO CORES|
|3 – CORE BOX||c – ARE USED TO MAKE HOLLOW CAVITIES OR HOLES|
a) 1-a, 2-b, 3-c
b) 1-b, 2-a, 3-c
c) 1-c, 2-b, 3-a
d) 1-c, 2-a, 3-b
Explanation: The following table shows correct matches.
|CORE – ARE USED TO MAKE HOLLOW CAVITIES OR HOLES|
|CORE PRINT – ARE USED TO PROVIDE SUPPORT TO CORES|
|CORE BOX – ARE USED TO PRODUCE CORES|
Sanfoundry Global Education & Learning Series – Casting, Forming and Welding.
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